Could be either a right hand drive Manta as sold through UK Opel dealers at the time, or a Vauxhall.

Front and rear views would decide (slots in panel above bumper on Opel - plain on Vauxhall), or position of rear number plate above (Opel) or below (Vauxhall) bumper. I am not aware of any other trim or colour differences apart from badges. For some time both were built in Belgium, side by side on the same track, by GM-Europe.